Steam rock-drill



(No Model.)

T. F. FARRELL.

STEAM ROCK DRILL. No. 390,578. Patented Oct. 2, 1888.

llNrTEn STATES PATENT OEEICE.

THOMAS F. FARRELL, OF PATERSON, NEW JERSEY.

STEANI ROCK-DRILL SPECIFICATION forming part of Letters: Fatent No. 390,578, dated October 2, 1888.

Application filed March S. 1888. Serial No. 266,50?. (No model.)

To all whom, it may concern:

Beit known that I, THOMAS F. FARRELL, a citizen of the United States, residing at Paterson, in the county of Passaic and State of New Jersey, haveinvented new and useful Improvements in Steam Rock-Drills, of which the following is a speeication.

This invention relates to an improvement in drills, and by means of this invention the construction of the actuating mechanism for the drill is simplified, as set forth in the following specication and claims, and illustrated in the accompanying drawings, in which- Figure l is a central longitudinal section of mechanism for actuating a drill. Fig. 2 is a sectionin the plane a" zr, Fig. l. Fig. 3 isa section in the planeyy, Fig. l. Fig. 4isasection in the plane .a z, Fig. 2. Fig. 5 is a section in the plane m x', Fig. l.

Similarletters indicate corresponding parts.

In the drawings, the letter A indicates a cylinder, and B is a piston having the ends C D. The steam-chest E has a snpply-pipe, F, and a valve having the heads G H I J is placed in the chest E. When the parts arein the posi tion shown in Fig. l, the steam passes from the supply-pipe F into the steam-chest E and between the valve-heads l J through the port K, and said steam pressing on the piston end D moves the piston in the direction of the arrow l on said piston in Fig. l. Vhen the piston B has traveled to the limit of its path in the direction of arrow 1, the head D has passed the duct N, and the steam from the port K, entering through the duct N into the steam chest E, presses on the valve-head G and moves the valve so as to cnt off the communication between the supply-pipe F and the duet K, and to allow the steam from the supply-pipe F to pass between the valve-heads G- H to the port L. The steam issuing from the port L presses on the piston end C and moves the piston in the direction opposed to that of the arrow l. This return motion of the piston continues until the piston has reached the position shown in Fig. 1, when the piston-head G has passed the duct Q, so that steam from the port L will pass through the duct O and willpress on the valve-head J, thus moving the valve back to the position shown in Fig. l,when the piston again moves in the direction of arrow l. An outlet, l?, enables any steam that may be conlined between the piston ends C D to pass to the exhaust M.

The piston B is tapped for the reception of a screw-shank, Q. On said shank Q is firmly mounted a toothed wheel, R. The detent S is provided with a head, T, and a channel, U, leads from the cylinder A to the detent-head T. When the piston is moving in the direction of arrow l, the steam from the port K, passing through the channel U, presses on the detent-head T and moves the detent S against the resistance of the spring V, so that the detent S engages the toothed wheel R and prevents said wheel,with the screw-shank Q, from rotating. The result is that the piston B,while moving in the direction of arrow l, rotates about the screw-shank Q, thusimparting a longitudinal and a rotary motion to the rod YV. When the piston B moves in the direction opposed to that of arrow 1, the steam-pressure on the detent-headTis removed,so that the spring V moves the detent S out of engagement with the toothed wheel R, leaving said wheel with the screwlshank Q free to rotate. The result is that during the motion of the piston in the direction opposed to that of arrow l the screwshank Q and wheel R rotate, while the piston B moves longitudinally without rotating.

The piston'rod XV is made to pass through the head X, having arecess containing the split or sectional rings Y. Screws Z are inserted laterally into the head X, and are made to press the rings Y tightly about the rod W, so

as to form a stufiing-box.

The ports K L, as seen in Figs. 2 and 3, are made to cross one anothermthat is to say, the port K leads to that part of the cylinder which is near the piston end D and the port L leads to that part of the cylinder which is near the piston end C. By locating the ports K L at the side of the cylinder, as shown, said ports can be readily made to clear the ducts N O and the outlet l?, thus making the casting of the ports K L and outlet l? easyl and simple.

By having the ports K L crossed, as shown, the stroke of the piston is shortened, since the piston will only travel in the direction of arrow l until the end D has passed the duct N, and said piston will only travel in the direction opposed to arrow l until the end C has passed the duct O. g

Another advantage of having the ports K L IOO at the side is that in drilling or forming the duets N O and outlet P the ports K L do not have their walls perforated or injured, thus avoiding the bushing which is required in case the Walls are perforated.

What I claim as new, and desire to secure l. The combination, with the cylinder, the piston, the valveheads G H l J, and the valvechest, ofthe ducts N O, the outlet P, and the two ports K L, extending, respectively, along the opposite sides of the cylinder, with their inner end' portions extending beyond or past each other and opening into the chest, substantially as shown and described.

2. The combination, with the cylinder, the piston, the valve, the steanichcst, and ports 4 direction and relieved of steamprcssure to release the wheel when the piston moves in the 25 opposite direction, substantially as described.

In testimony whereofI have hereunto set my hand and seal in the presence of two subscribing witnesses.

THOMAS F. FARRELL. [1.. s]

Witnesses:

W. C. HAUFF, E, F. KAsTnNHUnnR. 

